Why Doesn’t The FDA Require Adherence Programs?

The one thing that kept jumping into my head while thinking about the FDA’s decision to require REMS programs is why they don’t require adherence programs. They approve drugs based on clinical trials. In the clinical trials, we see unreal adherence rates that are never duplicated in the real world. If they saw the same adherence drop-off rates in the clinical trials, would they still approve the drugs? I would venture a guess that the answer would be no because the outcomes would be much less.

So, if drugs don’t work in people that don’t take them (as Dr. Koop would say), why do we have a bunch of drugs on the market that “don’t work”? Wouldn’t the FDA want to address adherence of these ~9,800 drugs where 99% of the spend is and which have a huge impact (~$290B) on the healthcare costs of the US in addition to focusing on the ~120 drugs that have safety concerns that require REMS?